Iraqi President Fuad Masum has arrived in the Iranian capital for an official visit expected to focus on the fight against the Islamic State (IS) extremist group and on economic relations.

Masum arrived in Tehran on May 12 with the ministers for trade, tourism, and the environment, as Iraqi government forces, backed by Shi’ite and Sunni militias, remains locked in battles against IS fighters.

Iran has sent weapons and military advisers to Iraq since the militants overran large parts of the country's north and west in June 2014.

Masum will be greeted by Iranian President Hassan Rohani at a ceremony in Tehran on May 13.

He is also expected to meet Supreme Leader Ayatollah Ali Khamenei during his visit.

Meanwhile in Baghdad, attacks on Shi’ite worshippers killed at least six people and wounded dozens of others.